package com.example.book.controller;


import com.example.common.dtos.ResponseResult;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;

@RestController
@Slf4j
@Api(tags = "图书图片上传控制器")
@RequestMapping("/common")
public class CommonController {

    @Value("${hgts.path}")
    private String basePath;

    /**
     * 文件上传
     * @param file
     * @return
     */
    @ApiOperation(value = "文件上传")
    @PostMapping("/upload")
    public ResponseResult<String> upload(MultipartFile file){
        log.info(file.toString());
        //file是一个临时文件，需要转存到指定位置，否则本次请求完成后临时文件会删除
        //获取原始文件名
        String originalFilename = file.getOriginalFilename();
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
        //使用UUID重新生成文件名，防止文件名称重复造成文件覆盖
        String fileName = UUID.randomUUID().toString() + suffix;

        //创建一个目录对象
        File dir = new File(basePath);
        //判断当前目录是否存在
        if (!dir.exists()){
            dir.mkdirs();
        }
        try {
            //将临时文件转存到指定位置
            file.transferTo(new File(basePath + fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }

        return ResponseResult.okResult(fileName);
    }
    @ApiOperation(value = "图片回显")
    @GetMapping("/download")
    public void download(HttpServletResponse response, String name){
        //输入流，通过输入流读取文件内容
        try {
            FileInputStream fileInputStream = new FileInputStream(new File(basePath + name));

            //输出流，通过输出流将文件写回浏览器，在浏览器展示图片
            ServletOutputStream outputStream = response.getOutputStream();

            //设置响应的类型
            response.setContentType("image/jpg");

            int len = 0;
            byte[] bytes = new byte[1024];
            while ((len = fileInputStream.read(bytes)) != -1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
            //关闭资源
            outputStream.close();
            fileInputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}
